# Draft California 2012 Integrated Report( 303(d) List/305(b) Report)

# Supporting Information

## Regional Board 6 - Lahontan Region

Water Body Name: | Irrigation Ditch, at Carson River Rd (Alpine County)
Water Body ID: | CAR6331001320110523161058
Water Body Type: | River & Stream

DECISION ID | 32055 | Region 6
Irrigation Ditch, at Carson River Rd (Alpine County)

Pollutant: | Temperature, water
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One lines of evidence is available in the administrative record to assess this pollutant. Twenty six of the 288 samples exceed the water quality objective. Samples were collected approximately once a month from June 1981 to June 2010. This sampling frequency seems adequate to establish baseline conditions (including diel, seasonal, annual and interannual variations in temperature) or to detect declining trends in the temperature regime if such trends exist. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Twenty six of 288 samples exceeded the objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32055, Temperature, water | Region 6
Irrigation Ditch, at Carson River Rd (Alpine County)
LOE ID: | 34073
Pollutant: | Temperature, water
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 288
Number of Exceedances: | 26
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Of the 288 samples collected, 26 of them exceeded the evaluation guideline for temperature in this water body.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The natural receiving water temperature of all waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such an alteration in temperature does not adversely affect the water for beneficial uses. For waters designated WARM, water temperature shall not be altered by more than five degrees Fahrenheit above or below the natural temperature. For waters designated COLD, the temperature shall not be altered.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: | Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference: | Fish introductions in CA: History and impact on native fishes. Davis, CA: University of CA, Davis
Spatial Representation: | Samples were collected from the SW-08 station.
Temporal Representation: | Samples were collected approximately once a month from June 1981 to June 2010.
Environmental Conditions: |
QAPP Information: | SWAMP QAPP
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 32053 | Region 6
Irrigation Ditch, at Carson River Rd (Alpine County)

Pollutant: | pH
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The Lahontan Basin Plan's narrative pH objective is an antidegradation-based objejctive that requires that there be no change greater than 0.5 pH units in waters designated for COLD and WARM beneficial uses. ( A pH range of 6.5 to 8.5 units applies to "all other waters.") Listing Policy section 3.10 contains directions for assessment based on trends in water quality. Though the LOE (34069) associated with this decision finds that 8 of the 295 samples exceed the water quality objective, this can not be determined with certainty because baseline conditions (normal ambient pH) has not been established for this waterbody. As such, it is more accurate to report the use rating for this decision as insufficient information not fully supporting. Staff recommend some trend analysis be completed on this data set before next listing cycle to determine the normal ambient pH for this waterbody. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. It can not be determined with certainty if 8 of 295 samples exceeded the objective because the water quality objective requires that a normal ambient pH be established for this waterbody in order to determine protection of the COLD beneficial use. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32053, pH | Region 6
Irrigation Ditch, at Carson River Rd (Alpine County)
LOE ID: | 34069
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 295
Number of Exceedances: | 8
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Numeric data generated from 295 minimums and maximums of pH data had 8 exceedences.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | In fresh waters with designated beneficial uses of COLD or WARM, changes in normal ambient pH levels shall not exceed 0.5 pH units. For all other waters of the Region, the pH shall not be depressed below 6.5 nor raised above 8.5. The Regional Board recognizes that some waters of the Region may have natural pH levels outside of the 6.5 to 8.5 range. Compliance with the pH objective for these waters will be determined on a case-by-case basis. [There is no site specific objective for pH for this water body]
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected from the the SW-08 station.
Temporal Representation: | Samples were collected approximately once a month from June 1981 to June 2010.
Environmental Conditions: |
QAPP Information: | SWAMP QAPP
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 32050 | Region 6
Irrigation Ditch, at Carson River Rd (Alpine County)

Pollutant: | Fecal Coliform
Final Listing Decision: | List on 303(d) list (being addressed by action other than TMDL)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Sources: | Source Unknown
Expected Attainment Date: | 2025
Date TMDL Approved by USEPA: | Waste Discharge Requirements and Monitoring and Reporting Program (RB6-2004-0010, WDID6A095900700) for South Tahoe Public Utility District, requires STPUD to conduct additional surface water (including this irrigation ditch) and groundwater monitoring. On an annual basis, STPUD must report corrective actions taken or planned, if any, which may be needed to bring the discharge into full compliance with the waste discharge requirements.
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.3 (Numerical WQO or standards for bacteria where REC uses apply) of the Listing Policy. If site-specific exceedance frequency is not available then defer to exceedance frequency described in section 3.2, table 3.2. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Thirty five of the 55 samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Thirty five of 55 samples exceed the objective and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

Line of Evidence (LOE) for Decision ID 32050, Fecal Coliform | Region 6
Irrigation Ditch, at Carson River Rd (Alpine County)
LOE ID: | 31806
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 55
Number of Exceedances: | 35
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Thirty-five (35) of the fifty five (55) samples exceeded the Fecal Coliform objective.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The Fecal Coliform concentration shall not exceed more than 40/100 ml.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The samples were collected in the Irrigation Ditch at Carson River Road in Alpine County.
Temporal Representation: | The samples were collected between March 2004 to June 2010.
Environmental Conditions: |
QAPP Information: | The samples were collected under the South Tahoe Public Utility District Laboratory Quality Assurance Program. Monitoring and Reporting Program NO. R6T-2004-0010
QAPP Information Reference(s):

DECISION ID | 32264 | Region 6
Irrigation Ditch, at Carson River Rd (Alpine County)

Pollutant: | Oxygen, Dissolved
Final Listing Decision: | List on 303(d) list (being addressed by action other than TMDL)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Sources: | Source Unknown
Expected Attainment Date: | 2025
Date TMDL Approved by USEPA: | Waste Discharge Requirements and Monitoring and Reporting Program (RB6-2004-0010, WDID6A095900700) for South Tahoe Public Utility District, requires STPUD to conduct addtional surface water (including this irrigation ditch) and groundwater monitoring. On an annual basis, STPUD must report corrective actions taken or planned, if any, which may be needed to bring the discharge into full compliance with the waste discharge requirements.
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Seventy one out of the 270 samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Seventy one of 270 samples exceed the objective and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy, which only allows for 45 exceedances for a sample size of 270. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

Line of Evidence (LOE) for Decision ID 32264, Oxygen, Dissolved | Region 6
Irrigation Ditch, at Carson River Rd (Alpine County)
LOE ID: | 34096
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 270
Number of Exceedances: | 71
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Numeric data generated from 270 computed averages of Dissolved Oxygen data yielded 71 exceedences.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | For waters with the beneficial uses of COLD, COLD with SPWN, WARM, and WARM with SPWN, the minimum dissolved oxygen concentration shall not be less than that specified in Table 3-6. COLD: 30-Day Mean: 6.5 mg/L
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected from the SW-08 station.
Temporal Representation: | Samples were collected approximately once a month from June 1981 to June 2010 and consequently consolidated into monthly samples.
Environmental Conditions: |
QAPP Information: | SWAMP QAPP
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan